In the prior art, laser annealing is used in ultra-shallow junction for ULSI MOS transistors using a pre-amorphization implant (by Si.sup.+ or Ge.sup.+ or Xe.sup.+) to create a shallow amorphous silicon (a-Si) layer under the surface of a substrate. The prior art then placed a gate and spacers over the shallow source/drain extensions and then used a separate process to create the deeper source and drain. The shallow source/drain extensions were desirable to prevent punch through. The deeper source/drains were desirable to allow silicidation. The prior art required separate processes to produce shallow source/drain extensions and deep source/drain junctions.
It would be advantageous to create a deeper source and drain and shallower source/drain extensions in a single process.